1. Field of the Invention
In general, the present invention relates to a process for separating components from gaseous mixtures. More particularly, this invention relates to a process for removing organic vapors from a gas mixture by contact with non-stoichiometric carbon-sulfur compounds under adsorption conditions.
2. Description of the Prior Art
It has been suggested to remove components from gaseous mixtures by using activated carbon as an adsorbent. (See, for example, W. D. Lovett and F. T. Cunniff, "Air Pollution Control Techniques: Air Pollution Control By Activated Carbon", Chemical Engineering Progress, Vol. 70, No. 5, pp. 43-47, 1974; R. J. Grant et al, "Adsorption of Normal Paraffins and Sulfur Compounds on Activated Carbon", AIChE Journal, Vol. 8, No. 3, pp. 403-406, 1962; H. M. Rowson, "Fluid Bed Adsorption of Carbon Disulphide", British Chemical Engineering, March 1963; F. G. Sawyer and D. F. Othmer, "Adsorption of Solvent Vapors on Commercial Activated Carbon", Industrial and Engineering Chemistry, Vol. 36, No. 10, p. 894, 1944; and J. C. Enneking, "How Activated Carbon Recovers Gas Liquids", Hydrocarbon Processing, Vol. 45, No. 10, pp. 189-192, 1966, the disclosures all of which are incorporated herein by reference.)
However, conventional activated carbons have been observed to have several limitations. For example, desorption of certain compounds (e.g., aromatic hydrocarbons) therefrom is difficult due to the high binding energy of said materials on the carbon. As such, regeneration of the spent activated carbon adsorbent becomes expensive in that large amounts of stripping gas are required for desorption.
It has also been suggested to use nonstoichiometric carbon-sulfur compounds to adsorb water vapor (see B. R. Puri and R. S. Hazra, Carbon, Vol. 9, pp. 123-134, Pergamon Press, Great Britain, 1971 and J. Siedlewski and R. Majewski, Przemysl Chemiczny, Vol. 55, No. 8, pp. 411-414, 1976, the disclosures of which are incorporated herein by reference). Nevertheless, it is believed that the particular adsorption process described hereinbelow has not heretofore been disclosed.